RISC OS 4 and all its bleedin’ relatives

Jeffrey said

kernel calling GraphicsV

Yeah I meant “is it likely that RO5 will implement the ROLVideoV API?” to which I think the answer is no.

Rick ummed

Ummmm….?

A vector call is, in effect, a negotiation. It is a late-binding, dynamic resolution of functionality to implementation, and that implementation can be piecemeal, collaborative, filtered or subverted from call to call.

That is valuable under some circumstances. It’s a lot of pointless overhead in other cases. Enabling negotiation of implementation for a particular display driver does not require that negotiation to happen every time you plot a triangle. It would be more efficient to use a jump table that is populated during a vector call, and then used direct… which is, ironically, what the ROL API does for the Point, HLine and VLine primitives, presumably because the vector overhead was too obviously onerous.

It’s not a great design, especially when you consider that (nearly) everything that goes through the ROLVideoV vector has already gone down the WrchV, SpriteV or ByteV vectors. Anyway, this is academic.

David appealed to history

In some ways…

I suppose that’s what Wikipedia is for. To say Acorn was a victim of ARM’s success is to fail to explain why Apple wasn’t. Acorn stopped making things that people wanted to buy, and for that they had no one to blame but their blinkered selves.

That is valuable under some circumstances.

Oh, we both know one can do all sorts of nifty things with vectors. Like trapping attempts to move or delete $.!Boot.Loader to make the machine reply “I’m sorry Dave, I can’t let you do that.”

It was this bit I was baulking at:

Enabling negotiation of implementation for a particular display driver does not require that negotiation to happen every time you plot a triangle.

In what possible way does that even make sense? It isn’t as if the user is going to be capable of hot-swapping the display in between calls to draw triangles with no other possible input to the system (in other words, if they were switching from LCD to CART, for example, assuming a machine where this is possible) then the act of switching would be some secret keypress or UI button and then is the time to negotiate stuff…

Anyway, this is academic.

True, but it’s great fun watching you report on pulling the thing apart to peek inside.

Acorn stopped making things that people wanted to buy

They, thankfully, hung on a little longer than The Great Purge when all those companies famous in the eighties disappeared. But, look at the world of commerce right now and all the well known brands closing down for whatever reasons. Maybe it’s just the cycle of things and the only reason Apple survived is because they were smart enough to sell the brand, not the product?
I mean, we know the usual heavyweights in the PC world like HP and Dell. Then along comes Asus, Lenovo, and more. Margins are thin and I reckon few people particularly care what there PC is as long as it runs Windows/Linux (delete as applicable) well and doesn’t have a known history of randomly blowing up. I’m tempted to think that however Acorn’s fortunes might have gone, the writing was on the wall. They weren’t selling PCs, they weren’t in a lucrative niche like assembly line automation, and they weren’t selling themselves as an exclusive brand, so…?

Worth remembering that Apple was only 90 days from going bankrupt in 1997….
https://thenextweb.com/apple/2010/06/02/steve-jobs-90-days/